Page 1
Tue
4OOl
UnaavARrABLE
PutsE
aENERATIR
Operation
Manual
1486 Highland Avenue,
Unit 2
Cheshire,
CT 06410
(203)27
2-3285 FAX:
(203)27
2-4330
Page 2
WARRANTY
Global
Specialties@ warrants
this
device
to
be
free
from
defective
material
or workman-
ship for
a period
of one
full
year from
the date
of
original purchase.
-
Global
Specialties@
under
this warranty
is
limited
to
repairing
the defective
device
when
returned
to
the factory,
shipping
charges
pre-
paid, within
one year from
date
of
original
purchase.
Units returned
to
Global
Specialties@
that
have been
subject
to abuse, misuse,
damage
or
accident,
or have
been
connected, installed
or
adjusted
contrary
to the instructions
furnished
by
Global
Specialties@,
or that have
been
re-
paired by
unauthorized
persons
will not
be
covered
bv
this warrantv.
Global
Specialties@
reserves
the
right
to
dis-
continue
models,
change
specifications,
price
or design
of this
device
at any
time
without
notice
and
without
incurring
any
obligation
whatsoever.
The
purchaser
agrees
to assume
all
liabili
ties for
any
damages
and
/
or bodily
inj
ury which
mayresultfromthe
use
ormisuse
of
this
device
by
the
purchaser,
his
employees,
or agents.
This
warranty
is
in lieu
of ali representa-
tions
or warranties
expressed
or implied
and
no
agent
or representative
of
Global
Special-
ties@
is
authorized
to assume
any
other
oUtiga-
tioninconnectionwiththe
sale and
purchase
of
this
device.
FACTORY
SERVICE
AND
Global
Specialties@
will
service and repair
this instrument
free
of charge
for a
period
of
one full
year,
subject to
the warranty
conditions
above.
To
obtain a return
merchandise
authorization
(RMA)
required
for
all returns,
phone
our
Customer
Service Department
for
an
RMA
and all
shipping
instructions:
Tel. 1-800-572-1.028
or write:
GLOBAL SPECIALTIES
1486 Highland Avenue, Unit 2
Cheshire, CT 06410
(203)272-3285
FAX:
(203)272-4330
ATTN:
CUSTOMER
SERVICE
DEPARTMENT
BREADBOARDING
SOCKETS
LIFETIME
GUARANTEE
All
Global
Specialties@
breadboarding
sockets are
guaranteed
for
life.
If a
socket
ever fails to
meet
your requirements,
return
it and
we will
replace
it,
NO
QUESTIONS
ASKED.
Specifications
subject to change
without
notice.
@
and TM
trademarks
are the
property
of INTERPLEX
ELECTRONICS,
INC., New
Haven,
CT.
Page 3
Page 4
TABLE
OF
CONTENTS
SPECIFICATIONS..
..PAGE
2
INTRODUCTION.....
.PAGE
4
DESCRIPTION.......
..PAGE
4
LOCATION
AND
DESCRIPTION
OF
OPERATING
CONTROLS............PAGE
5
CHECKING
OUT
THE
4OO1
.....PAGE
9
APPLICATIONS.....
...PAGE
14
CIRCUIT
DESCRI
PTION.......
REcALIBRATIoN
PRocEDURE
AND
;usE
nepLACEMENi............
B1BE
??
CIRCUIT
SCHEMATIC..........
...PAGE
27
SERV|CE
AND
WARRANTY
tNFORMAT|ON..........................................pne
e ze
LIST
OF
ILLUSTRATIONS
FIGURE
1.
Location
of
Operating
Contro1s.............
PAGE
5
FIGURE
2.
Run
lMode
and
com[lemented
waveforms..............
pAGE
5
l99l!
q
Trig
Mode
Waveforms..............
............PAGE
6
FIGURE
4.
Gate
Mode
Waveforms..............
......,...PAGE
6
FIGURE
5.
One-Shot
Mode
Waveforms..............
...PAGE
6
FIGURE
6.
Run
Mode
and
Squared
Waveforms..
..PAGE
7
FIGURE
Z.
Checkout
Configuration..........
..............PAGE
9
FIGURE
8.
Waveforms..............
.............PAGE
10
FIGURE
9.
Checking
Trigger
and
Gate
Modes.....
.PAGE
14
FIGURE
10.
Missing
pulse
Detector
Apptication..............
.......pAGE
15
II9yl_E 11
Amptifier
Frequency
Response
Test.........
..........pAGE
17
FIGURE
12.
Transmission
Line
Test...
...PAGE
1g
FIGURE
13.
Scope
Waveform
Patterns-Transmission
Line
Testing.......pAGE
20
FIGURE
14.
Case
Disassembly
and
Assembty
.......PAGE
25
FIGURE
1s.
Circuit
Schematic........
.
.
..........................:.
.pAGE
27
LIST
OF TABLES
IlPf_E
1.
Typical
square-wave
patterns
and
Interpretation...................pAGE
16
TABLE
2.
Power/Output
Retationships....................:.....
..........pAGE
17
Page 5
Frequency
Range:
Pulse
Width
and
Spacing
Controls:
Duty
Cycle:
Accuracy:
(Pulse
Width
and
Spacing)
(Amplitude)
Jitter:
Operating
Modes
(pushbu
tton
selectable)
Run:
Trig:
Gate:
One
Shot:
Square
Wave:
4OO1
SPECIFICATIONS
0.5
Hz
to
5 MHz
1O0nsec.-1sec
in
7
overlapping
ranges.
Independent
variable
width
and
spaiing
controls.
Two
concentric,
single-turn
verniers
provide
continuous
adjustment
between
ranges.
107-to-1
range,
cont.
adjustable
+5%
typical,tlso/o
@
max
vernier
setting.
+5o/o of
control
setting.
Less
than
0.1%+S0psec.
0.5
Hz
to
5 MHz,
frequency
settable
through
pulse
width/spacing
controls.
DC
to
approximately
10
MHz
from
external
source.
Generator
starts
synchronously
with
leading
edge
of
gate
signal-"One
Shot"
pushbutton
can
manually
activate
gate
in
this
mode.
Enables
manual"One
Shot"
pushbutton.
Square
wave
may
be
obtained
at the
outputs
by
depressing
"Square
Wave"
pushbutton.
Page 6
Complement:
Trig/Gate
Input:
Output:
Var
Out
TTL
Out:
Sync
Out:
Power:
Operating
Tem
perature:
Size
(WxHxD):
Weight:
Q{guts
may
be
inverted
by
depressing
the
"COMPL"
pushbutton,
without
losing
sync
time
reference.
NOTE:
pulse
spacing
controls
not
active
during
"Trigger"
and
"One-Shot"
modes.
TTL
compatible
input,
DC
coupled
logic
input:
pulses>2.4V
peak>4Onsec
wide.
Sine
wave
input:>1.7V
RMS<1OMHz.
Input
impedance:
400Q
max.
input:
r10V.
Amplitude,
0.S-10V,
adjustable
via
single
turn
vernier;
rise/fall
time
3Onsec;
impedande,
50CI
Fan
out,40
TTL
loads;
sink,
64mA
at
O.gV
maximum;
rise/fall
time:
less
than
2Onsec.
Amplitude
2.4V
minimum;
fan
out, 1O
TTL
loads;
sink,
16mA
at O.8V
maximum;
riseifall
time,
less
than
2Onsec;
sync
pulse
lead
time,
greater
than
2Onsec.
105-125VAC,
50/60
Hz
220-240VAC,
50i60
Hz
(Optionat)
0"Cto50"C
(calibrated
at 25"
C
t55"
C).
32"
F
to
122"
F
'(calibrate
d
al
72" F*9"
F).
10"
x
3" x7"
(254
x 76
x
178mm).
2.2tbs. (1
kg)
Page 7
INTRODUCTION
The
Global
Specialties
4001
Ultravariable
Pulse
Generator
is
a
reliable
low
cost
pulse
Generator.
lts
uncomplicated
rugged.design
and
high
quality
components
ensure
long
and
dependable
service.
The
4oo1
offers
these
feaiures:
Separate
TTL
Output
A
Variable
Output
from
O.5V
to 10V
5Q
Output
lmpedance
Pulse
Width
Range
from
lOOnsec
to lsec
DESCRIPTION:
The
Model
4001,
primarily
designed
as
a
pulse
or
clock
source,
is
compatible
with
lC
and
discrete
component
circuits.
lt
also
finds
application
as
a
syste.
sieppet
(One-
Shot
Mode),
gated
oscillator
(Gate
Mode),
or
prir"
stretcher (Tiigger
Mode).
With
a
minimum
of
adjustments,
the
4oo1
can
also
serve
as
a missirig
illse
detector
or a
frequency
discriminator.
The
output
can
be
complemented
or
converted
to
a
square
wave
with a push
of
the
button.
The
Model
4001
offers
two
Simultaneous
Independent
Outputs
(TTL
and
Variable)
with
rise
and
fall
times
less
than
30nsec;
2Onsec
TTL
compatible
leading-edge
Sync
pulse
output'
There
are
independent
pulse
width
and
pulse
spacing
controls
(both
selectable
form
lOonsec
to
lsec)
eliminating
incompaiible
frequenJy
ano
pulse
width
settings.
Also
on
the
panel
are four
pushbutton
selectable
operatind
mooe
switches
marked
(Run,
Trigger,
Gate
and
One-Shot).
Page 8
LOCATION
AND
DESCRIPTION
OF
Refer
to Figure
1
for
the location
of
all
operating
referred
to
throughout
the
text.
NOTE
All
pushbutton
switches
are
push-to-activate
switches.
1
2
34
5
'13
12
11
1098
FIGURE
1.
Location
of
Operating
Controls
POWER
Switch
and
LED
Indicator: (1)
MODE
Switch
(2)
NOTE
The
four
Mode
Switches(2)
are
mechanically
interlocked
allowing
only
one
switch
to
be
activated
at
a
time.
They
are
designated
RUN,
TRIG
ano
ofr-sHor.
RUN:
In
the
Run
mode,
the 4OO1
is
self-oscillating.
All
external
inputs
are
disconnected,
and
all
timing
controls
are functional.
(See
figure
Z)
aOpr3^.
20
nsec
1 l*
{
z.a
V Min.
SyncOut
n
n
n
n
:n
n
I
Run
TTL or
t-t
t-l
f-l
f-l
l-l
l-l
Mode
Var
Out
TTL
or
Complemented
Var
our
--l
l-'l
f-]
l-]
f-l
l-l
l-
FIGURE
2.
Run
Mode
and
Complemented
OPERATING
CONTROLS
controls.
These
numbers
will
be
*rrrorx l-E'|.-
-.-
-',
5,
1.f.
-,
19,
/
;Ai.ffi:/n
[( | l]--
aoor
eulse
GENERAToer
,\-/..
\lZ
o^rt[.rc
*
tY* ar rr!
out va.
ovr
Page 9
TRIG:
In
the Trig
mode,
the
4001
outputs
produce
a synchronous positive
going
output
pulse
for
each
positive
input
trigger.
The
output
pulse
width
is
adjusted
byihe
pulse
Width
and
Width
Vernier
controls.
The
output
puise
is
initiated
by
the
posltiu"-.dge
of
the
input
trigger.
When
the
mode
switch.is
in
the Trigger
mode,
the
pulse
Spacing
and
Spacing
Vernier
are
inactive. (See
Figure
B)
ve'
i"v-Y'
rrrv '
v'vv
Trig
TTL
or
Var
Oul
f
,,,n
I
tvtode
FIGURE
3. Trig
Mode
Waveforms.
GATE:
In
the
Gate
mode,
the
4991
outputs
produce
trains
of
pulses
for
the
duration
of
the
applied gallng
signal.
The
leading
edge
of
the
gating
signal
starts
the
output
pulse
!ai1
The
first
pulse
in
the
train
ii
synchronized'witti
teioing
edge
of
the
gating
signat.
Both
the Pulse
Spacing
and Pulse
wiotn
controls
the
program
pulse
train
parameters.
lf
the
gating
pulse
ends
while
an
output
is
present,
the lait
pulse
will
be
complemented.
(See
Figure
4).
I
2.4 V Min
lcate
.Irloi
l;il'"
Var
Oul
With
Lead
Edge
)
of
Gate
Signai
FIGURE
4.
Gate
Mode
Waveforms.
ONE-SHOT:
In
the
One-Shot
mode,
the mode
switch
is
latched
and
the
One-Shot
pushbutton
(-s)'when
pressed,.
initiates
an'output pulse.
Pulse parameters
are
set
by
the
pulse
Width
(11)
and
Width
Vernier
controls.,Pulse
Spacing
and
Spacing
Vernier
controls
are
not
active. (See
Figure
5)
Pushbutton
one Shot
---r,/
oepressed
lone-snot
.Irlol
Var
out
-l
Figure
5.
One-Shot
Waveforms.
6
l0
V
Max
Page 10
SQUARE
WAVE: (3)
when
this
button
is
depressed
the
output
is
converted
to a
square
wave.
The
output
now
changes
state
with
every
positive
edge
of
the
original
"piogrammed"
waveform.
This
divides
the frequency
of
the
signal
Oy
two.
All
inputs
and
controls
are
still
functional.
(See
Figure
6)-
TTL
or
Run
Mode
Var
out
i-t_i-i_ro*r"o
FIGURE
6. Run
Mode
and
Squared
Waveforms
COMPLEMENT:
(a)
When
this
button
is
depressed
the
TTL
and
Variable
outputs
are
automatically
complemented.
All inputs
and
controls
are
still
functionat.
1net.
Figure
2)
ONE-SHOT
MODE
SWTTCH: (5)
See
MODE
switches (2)
for
details.
AMPLITUDE
CONTROL:
(6)
The
AMPLITUDE
control
adjusts
the
amplitude
of
the vottage
at
the VAR
OUT BNC
connector
from
0.5
Volts
to 10
Volts.
VAR
OUT:
(7)
The
VAR
OUT BNc
connector
provides
a
convenient
means
for
interconnecting
the
generator
output
to its
destination.
The
VAR
OUT
signal
has
a
rise
and fall
time
of
3Onsec
and
output
impedance
of
50
ohms.
TTL
OUT:
(8)
The
TTL
Output
BNC
connector
is
fed
by four
TTL
gates
in
parallel,
providing
a TTL
fanout
of 40.
Rise
and
fall
times
are
less
than
20ns6c.
Both'TTL
and'vAR
ouT
pulses
are
derived
from
the
same
internal
source
and
are
svnchronous.
SYNC
OUT:
(9)
The
SYNC
OUT
BNC
connector produces
an
output
pulse
2onsec
wide
and 2onsec
in
advance
of
the main
output
pulses.
The
Sync
pulse
amplitude
is
a minim
um
ol 2.4
Volts
and
can
drive
10
TTL
loads.
Page 11
GATE\TRIG
INPUT: (10)
The
GATE\TRIG
input
terminals
are DC
coupled
to
the
4001
internal
circuitry.
The
input
signal
can
be
a
sine
wave greater
than
1.7V
RMS
or
a
positive
pulse
greater
than
2.4V
NOTE
Amplitude
must
not
exceed
tlOV.
WIDTH
VERNTER:
(11)
The
WIDTH
VERNIER
is
used
for
continuous
adjustment
of
pulse
width
between
the
limits
9f.
the range
set
on
the PULSE
wIDTH
sWtrcH.
A
stight
overtap
at
both
ends
of
the
Vernier
range
insures
continuous
adjustment
over
the
entire
seven
decades
of
pulse
width
adjustment.
PULSE
WIDTH
SWTTCH: (12)
The
PULSE
WIDTH
switch
is
used
to
select
output
pulse
widths
from
1oonsec
to lsec
in.seven
ranges'
When
used
in
conjunction
with
the
Width
Vernier,
continuous
adjustment
over
the
instrument
range
is
achieved.
SPACING
VERNTER:
(13)
The
SPACE
VERNIER
is
used
for
continuous
adjustment
of
pulse
spacing
between
the limits
of
the range
set
on
the
pulse
spacing
sr,vitch.
n
stight
ou"ri"p
at
both
ends
of
the
vernier
range
insures
continuous
adjustment
ouer
the
entire
seven
decades
of
pulse
spacing
adjustment.
PULSE
SPACING
SWTTCH: (1a)
The
PULSE
WIDTH
switch
is
used
to
select
output
pulse
spacing
from
1ggnsec
to
lsec
in
seven
ranges.
when
used
in
conjunction
wiin
the
SpACI-ruG
vrnrutrn,
continuous
adjustment
over
the
entire
instrument
range
is
achieved.
FLIP-UP
LEG
rM
:
(15)
Easily
raised
or folded.
Elevates
the front
of
the
generator
1
i/2
inches.
FUSE
HOLDER:
(REAR
PANEL)
The
fuse
post
is
mounted
to
the rear
panel.
(see
Figure
14).
Page 12
CHECKING
OUT
THE
4OO1
To
check
out
the
Model
4001
Pulse
Generator
the
following
equipment
is
required.
(See
Figure
7).
1.
A
dual-trace
oscilloscope,
100MHz
bandwidth
minimum.
(Hewlett
packard
Model
1740
or
equivalent)
2.
A
TTl-level
frequency
source.
(Global
Specialties
Model
2001
or
equivalent)
3' Three
BNC-to
BNC
cables
(Global
Specialties
Model
PSA-2
or equivalent)
4.
A
50
ohm
terminator.
Procedure
Plug
the 4001
into a power
source
of
the
proper
voltage
and
frequency. (105
to
11SVAC,
60Hz
or 210
to 230VAC,
50
to
6OHz)
Press
in
the
pOWrn
ON
switch.
LED
adjacent
to
the
switch
will
illuminate.
FIGURE
7.
Checkout
Configuration.
Step
A:
Set
the
controls
on the
4001
as follows:
CONTROL
Power
SW
Pulse
Width
SW
Pulse
Spacing
SW
Width
Vernier
Spacing
Vernier
Run
Mode
SW
Square
Wave
SW
Compl
SW
Amplitude
Cntrl
The
POSITION
ON
100ns
100ns
Xl
(fully
clockwise)
X1
(fully
clockwise)
IN
Normal
Out Position
Normal
Out Position
10V
(fully
clockwise)
o@
o
o
oo
oo
oB'3o
Y Fauln
n
loSo
Page 13
Step
B:
Connect
one
BNC-Io-BNC
cable
from
the 4001
TTL
OUT
BNC
to
the
oscilloscope
channel
"A"
input.
connect
the
second
BNC-Io-BNC
cabte
from
the 4001
syNc
our
BNC
to
the
oscilloscope
channel "B',
input.
Step
C:
Set
the
oscilloscope
in
the
ALT
mode
to
trigger
on
the rising
edges
of
the
,,61,,
input,
with
a
sweep
speed
of
50ns
per
division
or faster.
observe
that
the""syNc
purse
rise
and
fat
times
are ress
than
2ons.
Pulse
width
is
approximately
2Ons.
Amplitude
is
2.4V
minimum.
Rising
edge
of
the
syNc
pulse
leads
the rising
edge
of
the TTL
pulse
by
approximately
20ns.
Step
D:
Press
in
the
COMP
switch
on
the
4001.
observe
that
the""
Rising.
edge
of
the
syNc
pulse
leads
the falling
edge
of
the TTL
pulse
by approximately
20ns.
(See
Figure
g).
Width
-
1
gsec
_:l-l*_i
(
n
l<-
sPbcine r
sec
-->f
-:l
l.<-
width
l
sec
---->l
Spacing
1
zsec
FIGURE
8. Waveforms.
10
Page 14
Step
E:
Return
the
COMP
switch
to it,s
normal
position.
Observe
that
the.....
Rise
and
fall
times
of
the
TTL
output
are less
than
20ns.
NOTE:
some
overshoot
or ringing
may
have
been
observed
on
the TTL
signal.
This
is
a
result
of
the
undampened
transmission
line
effects
of
the
BNC
cabl6
and is
not
inherent
to
the waveform.
The
same
form
of
distortion
may
also
be
in
evidence
during
the
following
steps
where
the VAR
OUT
signal
is
used.
These
reflections
will
cease
to
exist
once
proper
impedance
matching
is
obtained.
Step
F:
Disconnect
the
BNC
cable
from
the TTL
our
and
connect
to VAR
our.
Rotate
the
AMPLITUDE
pot
from
its fully
clockwise position
to its
fuliy
counterclockwise
position.
Observe
that
the.....
waveform
amplitude
decreases
from
its
initial
1oV
value
to
a
o.5V
level.
Step
G:
Set
output
amplitude
to
5V.
Connect
the
50fJ
terminator
at
the
oscilloscope
"A"
channel
input
in-line
with
the
BNC
cable.
NOTE
Many
oscilloscopes
have
a
5OO
terminator
that
may
be
used
in
place
of the
external
terminator.
Observe
that
the....
output
amplitude
is
now
2.5V
and
that
ringing
previously
present
due
to impedance
mismatching
no
longer
lpfears.
NOTE
VAR
OUT
rise
and
fall
times
are
less
than
30ns.
observe
that
the""
urse
width
and
purse
spacing
are
each
100ns
xso/o.
1t_
Page 15
Step
H:
Rotate
the
WIDTH
VERNIER
to its
uX10"
position.
Note
that
the
pulse
width
is
now
lpsec
*15o/o
and
that
the
pulse
spacing
is
unchanged.
Press
in
the
coMp
switch
and
note
the
waveform
inversion.
Press
in
the
SQUARE
WAVE
switch.
Note
that
the resulting
waveform
has
a
pulse
width
of. 1.1psec
and
a
pulse
spacing
of 1.1psec,(the.r*if
the wIDTH
and
rf".ing
settings)
for
a
total
of 2.2p"s.
Return
the
SQUARE
WAVE
and
COMP
switches
to
their normat (OUT)
positions.
STEP
I:
Rotate
the
SPACING
VERNIER
to its "X10" position.
Note
that
the
pulse
spacing
is
now
lusec
t15%.
Change
PULSE
SPACING
and
pULSE
WTDTH
to 1ps.
Observe....
A
pulse
width
and
pulse
spacing
of lOpsec
+11o/o.
STEP
J:
Observe....
A
pulse
width
and
pulse
spacing
of 1ps
xlo/o.
Change
PULSE
WTDTH
and
pULSE
SPAC|NG
to 1Ops.
Observe....
A
pulse
width
and
pulse
spacing
of 10ps
r5%.
STEP
K:
Rotate
the
WIDTH
VERNIER
and
SPACING
VERNIER
to
..X10...
Observe....
A
pulse
width
and
pulse
spacing
of
l0Oprsec
t15%.
change
the
PULSE
wtDTH
and
pULSE
spActNG
to 1oops.
Observe....
A
pulse
width
and
pulse
spacing
of
lmsec
+1|o/o.
L2
Page 16
STEP
L:
Observe....
A
pulse
width
and
pulse
spacing
of
100ps
xilo/o.
change
the
PULSE
wtDTH
and
pULSE
spActNG
to 1ms
+\-5%.
STEP
M:
Rotate
the
WIDTH
VERNIER
and
SPAOING
VERNIER
to
,'X1O'..
Observe....
A
pulse
width
and
pulse
spacing
of lOmsec
+15"/o.
change
PULSE
wrDTH
and
pULSE
spAcrNG
to 10ms.
Observe....
A
pulse
width
and
pulse
spacing
of 100mse
c
x15o/o.
STEP
N:
Rotate
the
WIDTH
VERNIER
and
SPAOING
VERNIER
to
,,X1,,.
Observe....
A
pulse
width
and
pulse
spacing
of
lOms
+So/o.
change
the
PULSE
wtDTH
and
pULSE
spActNG
to
100ms.
Observe....
A
pulse
width
and
a
pulse
spacing
of 100ms
xlyo.
STEP
O:
Rotate
the
WIDTH
VERNIER
and
SPAOING
VERNIER
to
,,X10,'.
Observe....
A
pulse
width
and
pulse
spacing
of
lsec
xl}o/o.
change
the
PULSE
wrDTH
and
pULSE
spAcrNG
to
1ms.
Press
in
the
ONE-SHOT
mode
switch.
Momentarily
push
in
the
white
oNE-sHor
pushbutton.
Observe....
One
single
1Oms pulse
is
generated
for
each
actuation
of
the
pushbutton.
1_3
Page 17
STEP
P:
Press
in
the TRIG
mode
switch.
connect
a TTL-level,
l\z
signal
from
a TTL-level
frequency
source
to
the
GATE\TRIG
lN
connector
on
the 4001
pulse
generator
using
a
BNC
cabte.
Observe..
A 10ms pulse
occurring
at
the
2Hz
rate.
STEP
Q:
Press
in
the
GATE
Mode
switch.
Observe....
Pulse
bursts
occurring
at
a 2Hz
rale.
STEP
R:
Turn
off
the
power
and
disconnect
all
cables.
This
concludes
the 4oO1
pulse
generator
checkout.
Gate/Trigger
Pulse
Source
i-.-
L-
(a)
t")
4001
Under
Test
Figure
g.
Checking
Trigger
and
Gate
Modes.
APPLICATIONS
The
4001
Pulse
Generator
with
its
many
features
and
ease
of
operation
make
it
a
welcome
addition
to
any lab.
The
following
is
just
a
sampling
of
the varied
uses
of
the 4001.
oo
o
Al
V
oo
oo
t)
(J
s'so
EE.
L4
Page 18
Missing-Pulse
Detector
Program
the
4001
pulse
width
for
1Opsec.
Set
the input
trigger
pulse
repetition period
(.pnpl
to
Sprsec.
Each
time
the
trigger
pulse
goes
positive,-the
ioot
i.
reset
and
must
time
out
to its
full
10psec.
The
outputs
of
the 4001
remain
in
the
High
State.
lf
one
of
the
trigger
putses
is not
present
(missing)
the
4001
output
will
tim-e
out
to 1Opsec
and
then return
to its
low
state
until
the
next
trigger
pulse
occurs.
(see
Figure
10).
I
I
I
_>1logsec
FIGURE
10.
Missing
pulse
Detector
Application.
TRACING
DIGITAL
LOGIC
FLOW
The
4001
and
a
digital
logic
probe
such
as
the
Global
Specialties
Lp-B
make
an
excellent
troubleshooting
system.
Just
use
the 4001
as
a
signal injector
to inject
either
a
pulse
train,
a
single
one-shot,
or
the
complement
of
eitherl
Then
trace
through
the
circuits
with
the LP-3
and
quickly
find
the
defective
component.
ANALYZING
A
MICROPROCESSOR
PROGRAM
By
substituting
your
4001
for
the
microprocessor
system
clock
you
can
give
your
microprocessor
th_e
capability
of
stepping
through
iis
microprogiam
either
a
step
at
a
time
(in
the
One-Shot
mode)
or
at much-
reducdd
speed,
oy
uiing
tong
timing
periods
in
the
"RUN"
mode.
Note,
however,
that
some
microprocessors
have
a minimum
clock
speed,
below which
correct
operation
is
not
assured.
lf
in
doubt,
check
the
data
sheet
toi
tfre
microprocessor
that
you
are
using.
TESTING
RADIO
CONTROL
RECEIVERS
Proportional
radio
control
is
usually
implemented
by
sending
a variable
mark-space
ratio
low
frequency
modulation
on a radio
frequency
signal.-your
4001
may
be
used
to
simulate
the
radio
transmitter
when
testing
the low-irequency
stages
of
your
receiver.
The
4001
is
also
ideal
for
simulating
the
joystick
input
to
the
transmitter.
----l
t
/sec
f*
t'199::
Input
I
4oor
I
15
Page 19
AUDIO
TESTING
The
4001
again
shows
its
versatility
in
testing
audio
amplifiers.
Square
waves
are
used
in
audio
testing
to.
display
a wioe
rangjof
frequencies
simulianeously.
Square
waves
consist
of
a fundamental
frequency,
and
a
series
of
odd
harmonics
to
square
off
the
wave
shape.
Waveform
LF
Gain LF
Gain
l-{F
Gain HF
Gain
Damping
qr-
oK
OK
oK
OK
oK
alLOKHOK
H
^
HOKLOKH
+'oKHoKLH
l:l"
OK
L
OK H
H
'az'
H H
L
L
H
qJ-
H
L
L
H
H
4.LHHLH
'"u
oK
oK H
OK
OK
'-'Ll-
OK
OK H
OK
L
t-
OKOKHOKLL
riroKoK*oKL
'Sharp
Cutoff
or
Peaked
L
=Low
LL = Very
Low
H
=
High
OK= Suitable
Proper
TABLE
1.
Typical
Square
wave
Patterns
and
an Interpretation
of These
Shapes.
For
an
amplifier
to reproduce
a
square
wave
it
must
have
a flat
frequency
response
from
0.1F
to 10F
where
"F"
is
the
fundamental
frequency
of
the
square
wave.
The
traditional
test
frequencies
are
SOHz
for
the low
frequency
test
and
1gKHz
for
the
high
frequency
end.
(See
Table
1)
connect
the
4001
to
the
amplifier
under
test
as
shown
in
Figure
12
and
observe
the
output
on
the
scope.
Table
2
shows
the
table
of
power
and
voltage
relationships
for
40
and
SOspeakers.
lt
also
liststhe
output
voltage
level
for
lOdB
below
the maximum
output
of amplifiers
with
different
power
ratings.
bhoose
the rating
closest
to
the
amplifier
under
test.
Testing
at 1OdB
below
maximum
output
ensures
that
the
amplifier
will
not
be
in
saturation.
This
level
is
approximately
2lS
of
the
full
power
output.
16
Page 20
o
o
oo
oo
Amp
Under Test
FIGURE
11.
Amplifier
Frequency
Response
Test.
TABLE
2.
Power/Output
Relationships
L7
Power
Ratings
(RMS)
Output
(RMS)
8(l
4J)
E2
Full
Output
l0
dB Below
Max
Output
1W
5W
10w
20w
50w
100
w
2W
10w
20w
40w
100
w
200 w
8V
,40
v
80v
160
V
400
v
800
v
2.8V
6.3 V
8.9
V
12.6
V
20.0
v
28.0 V
2.3
V
5.2V
7.3
V
10.3
V
16.3
V
23.1V
Page 21
TESTING
TRANSMISSION
LINES
lf
a
transmission
line
is
not
terminated
at
the
far
end
by
its
characteristic
impedance,
reflections
will
occur.
This
phenomenon
can
be
used
to find
faults
on
transmission
lines'
Using
your
4001 you
can
find
out
if
the
cable
under
test is
open,
or
short
circuited,
and
with
some
simple
calculations,
you
can find
the lengih
of
tn"
cable.
Equipment
1-4001
Pulse
Generator
1-50Q
coaxial
cable
to
be
tested(=1Om
long)
1-oscilloscope
1-passive
probe
10:1
1-50Q
termination
1-adaptor
banana
female-BNC
male
1-BNC
T
connector
Banana Female
10:l
Passive
Probe
FIGURE
12.
Transmission
Line
Test
Set
up
the
equipment
as
shown
in
Figure
12.
Set
the
4001
to:
Amplitude-6.5V
Pulse
width
time-Sprsec
Pulse
space
time-S
l-rsec
Square
Wave-engaged l
(use
VAR.
output
connector)
Set
the
scope
to:
Vertical
Display-
1 V/cm
Input
Coupling-DC
Trig
Source-lnt
Trig
Mode-Audio
Trig
Level-Adjusted
Sweep
Time-2psec/cm
1_8
oo
o
o
oa
oo
Page 22
With
the far
end
open,
the
scope
should
display
a
signal
as
shown
in
Figure
13.
The
final
amplitude
is
reached
in
two
steps.
At
the
moment
the
4001
meets
the
50e
of
the
cable
itself,
the
output
is
at nominal
value
(midscale
dots
B
on
Figure
13)
and
a
reflection
takes
place
at
the
open
end.
When
this
reflection
feeds
back
to
the
pulse
generator
output,
it
tells
the 4001
that
the
far
end is
open,
and
the
open
circuii voltage
of
the 4001
appears.
Now-change
the Time/Div
of the
scope
to 0.1psec
and
observe
the
signal
in
Figure
13.
The
time
between
points
"A"
and "B"
is
the
time
it
takes
for
the miising
sigriat
to
reach
the
open
end
and return.
For
example,
assume
that
(as
in
Figure
tsny
lne
reflection
takes
12Onsec.
lt is
known
that
ihe velocity
of
a
signat
in
I
coaxial
cable
is
about
0.7c
(c=3x
108
m/sec).
lf
the
cable
has
the length
"L'iit
will
take 2uo.7c
before
the
signal
returns
as
a reflection.
Using
the time
observed
on
the
scope
the
cable
length
is
calculated
as shown:
2l
,=ffC
where "T,,
is
TIME
for
Reflection
Solving
for "L"
we
get:
t_0.7cT
-_-2
2=
(0.
7)
x(3x/08/
ms?c)
x(
120
xf2'sec)
2
Remember
that
the
accuracy
of
this result
is
determined
by
the Time-Base
accuracy.
9!fn
clrcuiting
the
end
of
the
cable
results
in
the waveform
shown
in
Figure
138
and
13C'
After
12Onsec
the
4001
"knows"
that its
output
is
short
circuited
and
the voltage
drops
to
zero.
The
cable
load
influences
this
ideal
behavior
and
zero
means
"almost"zero.
The
cable
load
influences
this
ideal
behavior
and
zero
means
"almost,,
zero,
which
can
be
noticed
from
the
offset
level
with
respect
to
the
start.
Terminating
the
far
end
with
5OO
results
in
the waveform(shown
in
Figure
1gD).
Matching
the
far
end
of
the
cable
with
a
resistor
equal
to
itre
characteiistic
impedance
completely
eliminates
reflections
from
the
far
end, iesulting
in
a
perfect
square
wave
at the
generator
end
of the
cable.
L9
Page 23
2rceclDiv
<->
-1
\A
I
A
"u"Y-
L
L
-
FIGURE
13.
scope
waveform
patterns-Transmission
Line
Testing.
0.1psec/Div
<--+
t
ft-
-B
I
-A
0
'olts
FIGURE
13A.
scope
waveform
patterns-Tnansmission
Line
Testing.
20
Page 24
2rcec/Div
€
0VcIts
r
tr
J\
,E
J
FIGURE
138.
scope
waveform
patterns-Transmission
Line
Testing.
0.'l6ec/Div
€
0Vr
tlts
.
-:t F
-
tl
I.;;f.T
2nd
Re
?
t
rfleclion
tl
\- f
1r
;t
Reflectior
tl
FIGURE
13c.
scope
waveform
patterns-Transmission
Line
Testing.
2L
Page 25
2
psec/Div
<+
r
I
0V(
tts
J
't
FIGURE
13D.
Scope
Waveform
Patterns-Transmission
Line
Testing.
CIRCUIT
DESCRIPTION
Figure
15
shows
the
schematic
diagram
of
the
4001
Pulse
Generator.
The
heart
of
the
pulse
generator
is
the integrated
circuit
A-1
dual
monostable
multi-vib
rator
#74123.
The
two
monostable
multi-vibrators
are
cross-coupled
from
the "e,,
output
of
the
first
to
the "A"
input
of
the
second
and
vice_versa.
Anti-Latch
Circuit
Operation
The
cross-coupled
monostabled
multi-vibrator
circuits
as
long
as
their
,,8,,
inputs
are
high'
However,
since
the
coupling
between
the
two
circuits
ii
purely
Dc
it
is
possible
for
he
oscillator
to
latch-up.
The
froblem
is
overcome
by
a special
triggering
cir:cuit
!9t
is
gated
on
if
a1
fails
to
osciilate.
Transistors
Q3
and
e4
form
a hook
oscillator.
R30
and
R32
bias
the
base
of
Q3 to 1/2Vcc
while
the
emitter
of
e3
is
controiled
by
R28
and
R29.
These
resistors
are
connected
to
the
e
output
of
the
nt-t
ano 41-8.
As
long
as
41
oscillates,
one
of
the
Q
outputs
will
be
high.
The
average
voltage
at
the
emitter
of
Q3 will
be half
the
Q
high
voltage.
This
holds
the
emitter
of
e3
more
negative
than
its
base,
and
e3
is
tut
off.
lf
the
oscillator
stops,
b-o!h
Qs
go
high.
Q3 emitter
voltage
rises
above
its
base
voltage
and
starts
to
conduct.
Q3
and
Q4 turn
on
and
latch,
dis;harging
Cre.
ns
eB and
e4
recover
from
the latch
condition,
the "B"
input
of At-n goes
high,
forcing
e
of 41_A
low,
turning
off
the
hook
circuit
and
restarting
the
oscillator.
22
Page 26
Timing
Circuit
Operation
The
timing
of
A1-A
is
controlled
bythe
selection
of
capacitors
C1
throughcT
and
R1
through
R10.
The
timing
resistor
R9
or
R10
and
the
trim
pots
R1
and R7
set
the range
for
Rg,
the
Spacing
Vernier,
Jor
each
of
the
pulse
spacing
switch
positions.
41-B
timing
system
is
the
same
as
A1-A.
Mode
Switch
Operation
Run
Position
ln
the run
mode,
53 removes
the
5 volts
from
the
input
to A5-B
causing
the
output
to
go
high,
enabling
the
oscillator.
Trig.
Position:
In
the
trig'
position,
54
applies
5 volts
to
R31,
Q4
saturates
and
shorts
the,,B',
input
of
the.A1-A
to
ground,
disabling
41-A.
When a positive
trigger
pulse
appears
at
J4,
e5
emitter
goes
high
and
A5-A
low,
A5-B
goes
high,
triggeiing
41-B
on.'
Gate
Position:
ln
the
gate
position,
55
ties
both
the
base
of
Q3 and
the "8"
input
of A1-A
to
the
S
volt.line
through
a 1K
resistor
(R33)
turning
off
Q3 and insuring
that
41-A
is in
the
oscillator
mode.
To gate
the
oscillator
on,
a
positive
voltage
is
applied
to
J4, which
via
emitter{ollowed
Q5 causes
A5-A
to
go
low,
A5-B
to
go
high,
and'the
oscillator
to
start.
The
oscillator
will
continue
to run
while
the
gate
signal
is
present.
When
the
gate
is
removed,
the
oscillator
completes
its
final
cycle.
One-Shot
Position:
The
pushbutton
fires
?
J-K
Flip
Flop (A2-A)
whose
output
turns
off
e5
through
CR2
and
R44.
This
manuaily
simurates
the inpui
of
a
triggei
purse.
Output
Circuit
Operation
TTL
Out:
The
TTL
output
is
derived
from
four
two-input
NAND gates.
A
4.7?
resistor
limits
the
output
drive
to 40
TTL
loads.
Var
Out:
Q2
is
the
final
driver
for
the VAR
output.
The
collector
of
Q2
is
tied
to Vcc
while
the
base
is
tied
to
the
collector
of
Q1 through
a 47Q
resistor.
The
collector
of
e1
is
tied
high
through
a
330Q
resistor
and
is
also
shunted
to
ground
by
a 2.SK
a amptitude
pot.
Q1 and
cR1
also
provide
active
pulldown
for
the
output
when
it
is
low.
The
output
is
fed
via
a 47o
resistor, providing
the
correct
impedance
and
overload
protection.
23
Page 27
Sync.
Out:
The
inputs
of
A4-D
are
connected
to
a timing
chain
consisting
of
3 TTL
gates
(AO-
A,A3-8,A4-A)
and
R39,C19.
The
output
of n-s-o
is
normally
high.
When
it
goes
low,
there
will
be
a brief
interval
before
the
signal
reaches
te
ortpi,t
of
A4-A
in
which
neither
input
of
A2-D.will
be high,
and
sJa
sync
wilr
be
generated.
Depending
on
the
position
of
the
complement
switch,
the first
trinsition
of
ine
output
witieither
be
simultaneous
with
the
falling
edge
of
the
sync
pulse
or lsnsec
after
it.
Power
Supply:
A
plug-in
type
power
supply
supplies
raw
DC,
plus
(+)
and
(-)
through
the
power
switch
direcily
to
the regulators.
RECALIB
RATION
PROCEDURES
Fuse
Replacement
The
4o01
is
protected
by
a type
3AG
slo
blo 114
amp
(1/8
amp
for
230V)
25oV
power
fuse'
The
fuse
is
accessible
at
the rear
panel
of
the'unit.
lf
replacement
of
the fuse
should
become
necessary,
follow
this
procedure:
1.
Disconnect
the
AC
power
cord.
2'
Use
a
screwdriver
to remove
the fuse
cap
holding
the fuse
and
remove
the fuse.
3. lnsert
fuse
with
correct
rating.
NOTE:
New
fuses
seldom
fail
without
malfunction
of
the instrument.
Repeated
replacement
of
the fuse
without
correcting
the
problem
may
cause
further
damage.
Case
Disassembly
and
Assembly
To
open
the
case,
turn
the
unit
upside
down
with
the
rubber
feet
facing
up
(see
Figure
14).
Remove
the
four
pads
from
ihe
plastic
feet.
Remou.
tn"
;;;";;
i;"m
the
center
recess
of
each
of
the
four
feet.
Note
The
flip-up
leg
will
automatically
come
free
with
the
front
feet.
Carefully
separate
the
two
halves
of
the
case
and recalibrate
the
unit.
To
close
the
case,
lower
the
case
bottom
and
guide
the front
and rear
panels
into
their
slots.
Position
the rubber
feet
as
illustraied
and
screw
the
two
halves
of
the
case
together.
Do
not
overtighten
screws.
Instail
the
four
rubber
pads.
24
Page 28
Recalibration
Procedure
Bgfore
being
shipped, your
4001
Pulse
Generator
went
through
a very
thorough
series
of
tests
and
calibration.
lf
recalibration
becomes
necessary,
f|llow
the instructions
outlined
below
carefully.
Do
not
attempt
to recalibrate
this'unit
unlessyou
have
e19ugh
experience
in
ihe
use
of an
oscilloscope.
See
warranty
(back
cover)
for
limits
of
liability.
During
this recalibration
procedure,
refer
to Figure
1,
control
Locations:
1.
Disconnect
all
cabres
from
the
40-01.
Remove power
cord from
wail
prug.
2'
Remove
the
top
case
half
as
outlined
in
the
Case
Disassemory
piocboure.
(See
Figure
14)
Fuse Holder
And
Llne Cord
FIGURE
14.
Case
Disassembly
and
Assembly
3'
Reconnect
power
and
connect
the
oscilloscope
to
the
TTL
ouT
BNC
on
the 4001.
25
Page 29
4.
Set
up
4001
front
panel
as follows:
CONTROL
POSITION
Power (1)
ON
Mode
(2)
RUN
Pulse
Width
Sw
(12)
100ns
Pulse
Spacing
SW
(14)
100ns
Space
Vernier (10)
X1
Width
Vernier
(11)
X1
Square
Wave (3)
OUT
Comptement
(4)
OUT
5. Adjust
R17
for
a
pulse
width
of 10Ons
r5o/o.
6.
Adjust
R7
for
a
pulse
spacing
of 10Ons
xlo/o.
7'
Switch
PULSE
WIDTH
and PULSE
SPACING
controls
to
their
1ps
positions.
B.
Adjust
R16
for
a
pulse
width
of 1ps
+So/o.
9.
Adjust
R6
for a pulse
spacing
of 1ps
xlo/o.
10'
Switch
PULSE
WIDTH
and-PULdE
SPACING
controls
to their
1oprs positions.
11.
Adjust
R15
for
a
pulse
width
of
10ps
5%.
12.
Adjust
R5
for
a
pulse
spacing
of 16ps
5%.
13'
Switch
PULSE
WIDTH
anO
pUtSE
SPACING
controls
to
their
100ps positions.
14.
Adjust
R14
for a pulse
width
of 100ps
xlo/o.
15.
Adjust
R4
for a pulse
spacing
of lObps
l:lo/o.
16'
Switch
PULSE
WIDTH
ano
putsr
SpnCtruG
controls
to
their
1ms
positions.
17.
Adjust
R13
for
a
pulse
width
of 1ms
xlo/o.
18.
Adjust
R3
for
a
pulse
spacing
of 1ms
xlo/o.
19'
Switch
PULSE
WIDTH
ano
pUtSE
SPACING
controls
to
their
1Oms
positions.
20.
Adjust
R12
for
a
pulse
width
of 1Oms
xl"/o.
21.
Adjust
R2
for
a
pulse
spacing
of
lOms
+So/o.
22'
Switch
PULSE
WIDTH
ano
putsE
SPACING
controls
to
their
100ms
positions
23.
Adjust
R11
for
a
pulse
width
of lOOms
+5o/o.
24.
Adjust
R1
for
a
pulse
spacing
of 100ms
xlo/o.
25'.Turn
off
power,
disconnect
ail
cables
from
the 4001,
and reassemblethe
case
as
outlined
in
the
Case
Reassembly
proceclure.
This
completes
recalibration
of
the
4001.
26
Page 30
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Page 31
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